Propulsion systems have been in use for years. See U.S. Pat. No. 5,063,735 to Colgren. The typical propulsion systems can include solid propellant motors, liquid propulsion engines, jet engines, and a combination of jet engine and solid motor such as solid propellant gas generator to start a jet engine and Rocket-powered ducted fan engine.
A main problem with conventional solid propulsion systems are the difficulties in thrust control. Another problem with conventional solid propulsion systems are complications involved in the reuse of solid motor case and other parts. Another problem with conventional solid propulsion systems is that the chamber enclosing the solid charge must be strong enough to withstand the heat and high pressures of combustion.
A problem with liquid propulsion rocket engines is that they contain volatile, toxic, corrosive and/or cryogenic propellants. Hence the engine is usually filled a short time before firing, thus requiring complicated and lengthy pre-firing preparations.
A problem with Rocket-powered ducted fan engine is that it can work only as a toy vehicle power plant. Also, only about fifty percent of exhaust gases are available for useful propulsion.
The prior art devices described above would not as suitable for providing a useful solid propulsion method that would have the advantages of both solid and liquid propulsion engines. Additionally, these prior art devices cannot make use of either solid chemical propellants or fissionable nuclear material as the fuel.